Note the rear-view mirror!
I rarely wear more than two layers. Almost never in fact. A good set of poly fleece pants and a wicking shirt topped by an uninsulated rain jacket is sufficient down to 0 f. Below zero I switch to a warmer jacket and thicker pants, but I still generate enough body heat to stay toasty. My eyeball did freeze shut one time, otherwise I haven't been injured by the cold. I'm built like a marine mammal. I love the cold!